Chia Cars!

RAY: I stole this puzzler from Mark Warren of Worcester, Massachusetts. Here it is:

In 1993, a book was published about methods to make industrial production ecologically friendly. In it the author mentions an auto prototype proposed by a leading automobile executive.

If the proposed car were actually put into production its body would be made of soybean plastic, it would be powered by ethanol, and would run on tires made from goldenrod. The car would in fact be biodegradable. We would, said the executive, be growing our own cars.